We used to buy ten cases at a time of wd-40 but it seems that there is a lot of trouble with the cans they always seem to lose the spray quality you can feel there is still oil in there but you can't always use it because it wont come out of the can ..Also the new tops fall off and dont always work as they should...I have heard this from a lot of people including a major Locksmith group that also stopped using it after over 20 years because of the same reason